This invention relates generally to the field of disposable and nondisposable medical syringes. More specifically, the present invention relates to a means for preventing movement of a disposable syringe plunger element relative to the body of the syringe, whereby the syringe may be pre-loaded with a fluid medicament to a required dosage level, and thereafter conveniently carried in a pocket or handbag without the necessity of carrying a complete medicament injection kit. While the invention is useful in a wide variety of applications, it is particularly suitable for use in conjunction with the administration of medicaments for diabetes, blood thinning, growth hormones, veterinary injections, and the like.
Many drugs used to alleviate the symptoms of a number of diseases or medical conditions require frequent injections. The most widely known example of such a disease is diabetes, although also included in this category are diseases and conditions such as juvenile growth hormone deficiency, migraine headaches, arthritis, penile dysfunction, and certain severe allergic reactions. Often these therapeutics are proteins or other molecules, which are not amenable to oral administration.
Diabetes is a disease wherein the body is unable to regulate the transport of glucose from the bloodstream into the cells of the body for use as a cellular fuel. As a result, diabetics often have too much glucose in their blood. The resulting buildup of glucose in the bloodstream can lead to serious health problems, including heart disease, blindness, kidney failure, and lower extremity amputations. It is estimated that about 16 million people in the United States alone suffer from diabetes, which means that one in 20 persons has the disease. About 385,000 people in the United States die each year from the disease, making it the sixth leading cause of death by disease and the seventh leading cause of death overall. The economic cost of diabetes is staggeringxe2x80x94the American Diabetes Association estimates that the health cost of diabetes runs between $92 billion and $138 billion annually. One study predicts that the incidence of diabetes worldwide will increase from the current 2.1% to over 3% by the year 2010, resulting in an estimated total of 220 million cases worldwide.
There are several different types of diabetes. Type 1 diabetes results when the pancreas either does not make insulin, or the body destroys the insulin that is made. In Type 2 diabetes, the pancreas makes sufficient amounts of insulin, but the cells cannot use the insulin. Type 1 diabetes is also called xe2x80x9cinsulin-dependent diabetes mellitusxe2x80x9d, because persons with this type of diabetes require insulin shots. Type 1 diabetes is relatively rare, occurring in less than 10% of persons with diabetes. Type 2 diabetes is termed xe2x80x9cnon-insulin-dependent diabetes mellitusxe2x80x9d, because at least initially, the persons with this type of disease do not require insulin shots. However, as many as 40% of the persons with Type 2 diabetes will require insulin shots as their diseage progresses. Type 2 is by far the most common form of diabetes. Over 90% of persons with diabetes have Type 2 diabetes. Other types of diabetes may develop as a result of pregnancy, specific genetic syndromes, surgery, drugs, malnutrition, infections, and other illnesses. These cases account for 1-2% of all diagnosed cases of diabetes.
Diabetes is defined as a medical condition characterized by fasting plasma glucose levels greater than or equal to 126 mg/dl of blood plasma. Diabetics must monitor their blood glucose levels on a regular basis. To maintain their blood glucose within normal bounds, diabetics must combine careful attention to diet, regular exercise, and frequent injections of insulin. If their blood glucose is outside the normal levels, diabetics may experience disabling complications.
Diabetics must carry their own supplies for insulin injections with them when they are not at their home or other location where they can safely store their supplies. These supplies include one or more syringes, sterile swabs, and liquid supplies of insulin. The supplies are either carried loose, or in a kit which includes a casing element. When required, the syringes are removed and loaded with insulin for injection, and the dose is administered. The supplies are relatively bulky and inconvenient, and their use often requires finding a relatively private location having a surface upon which to place the supplies during use. Furthermore, the user must retain at least a portion of the supplies even after the required dose has been injected.
Insulin pens are often used in place of syringes. These devices are prefilled with an insulin cartridge to inject a required dose. The pens are filled with a certain number of doses, and may or may not be ultimately disposable. The pens do not require the user to carry a bulky vial of insulin. However, the pens are not immediately disposable, and like the kit described above must be carried with the user even after the required dose has been injected. The pens are also more expensive than syringes, and the insulin for use with the pens more expensive than the insulin used with syringes. Furthermore, the pens are bulkier than individual syringes. Since needles and insulin cartridges made specifically for the insulin pens must also be purchased and carried by the user, the pens do not solve the problems of having to carry supplies.
Also available are preloaded syringes, from companies such as Vetter Pharma-Turm. However, these syringes are prefilled by the manufacturer, not the user, and the user is not able to adjust the volume of liquid in the syringe without breaking the seal. Furthermore, these devices are locked with a cap on the needle end of the syringe, which means that no needle may be attached to the syringe prior to transport. The needle must be attached to the syringe after the cap is removed, adding an additional step and supplies to the process.
Other references disclose devices and methods for encasing a syringe for safe transport. U.S. Pat. No. 5,519,931 (Reich) discloses a complex device for transporting a syringe filled with a radioactive material. The device includes a sharps container for holding the syringe and a radiopharmaceutical xe2x80x9cpigxe2x80x9d for holding the sharps container. U.S. Pat. No. 4,886,497 (Scholl, Jr.) discloses a container for transporting hypodermic syringes. The container includes a first sealed position for ensuring that the container has not been tampered with before use of the syringe, and a second position for sealing the syringe after use for transport and disposal of the used syringe. U.S. Pat. No. 4,634,428 (Cuu) teaches a cover for a disposable syringe that allows rotation of the needle after use for rendering the syringe unusable. U.S. Pat. No. 3,937,219 (Karakashian) and U.S. Pat. No. 3,207,302 (Hobbs) disclose methods of packaging syringes prior to use. These methods are typically awkward and not suitable for use with individual syringes.
In addition, much effort has been focused on developing syringes that avoid the problems of accidental needle sticks and illicit re-use of syringes. For example, U.S. Pat. No. 5,891,092 (Castellano) discloses a disposable syringe that provides a slideable protective cover and a disabling member. After an injection is made using the syringe, the disabling member breaks the sealing, diaphragm of the plunger rod, so that the syringe is rendered incapable of delivering another injection. The slideable protective cover also slides forward to cover the needle and prevent accidental needle sticks. U.S. Pat. No. 5,183,466 (Movern) discloses a hypodermic syringe having a plunger assembly that enables the syringe to be used in a conventional manner but not reused. The syringe barrel contains a plunger lock that engages the plunger piston after filling the syringe with a liquid and allows discharge of the liquid, but thereafter locks the plunger in place and prevents refilling of the syringe. U.S. Pat. No. 4,915,692 (Verlier) describes a non-reusable syringe that accomplishes the same end as Movern. U.S. Pat. No. 3,890,971 (Leeson et al.) discloses a safety syringe that incorporates both a plunger lock and a lockable needle cover to render the syringe incapable of reuse. U.S. Pat. No. 5,506,015 (Fredericksen et al.) discloses a tamper-evident closure seal for syringes that provides an improved method for removing the seal from a release liner without sacrificing the ability of the seal to either adhere strongly to the syringe or to show evidence of tampering with the seal. However, these syringes do not address the problem of how to transport preloaded medicament syringes without the need for a bulky apparatus or retaining anything associated with the injection after use.
In view of the popularity of the disposable syringes, there is a great need for a convenient device that would allow the user to prefill syringes with a desired volume and after use, discard the used syringe without the need to retain anything associated with the injection. The present invention fulfills this need.
The present invention provides a small, simple device for locking a syringe plunger in place along a syringe barrel. When in place, the device enables a preloaded syringe to be carried anywhere and used immediately, without the need to load the syringe or carry vials of the desired medicine. Furthermore, after use the syringe may be simply discarded, as any other used syringe. Multiple syringes may be loaded in this fashion and carried, relieving the user of the need to carry medicament vials or bulky supplies with them. When used for insulin injections, the present invention also enables the patient to use the less expensive insulin vials, as opposed to the more expensive vials associated with the use of insulin pens. Finally, the present invention allows the user to transport premixed insulins that are not available to the users of insulin pens. As a result, greater flexibility is afforded the patient by the use of the present invention.
Accordingly, it is an object of the present invention to provide a syringe plunger immobilizing device, comprising a first hollow member, a second hollow member, a means for hingeably connecting the first hollow member to the second hollow member, and a means for holding the first hollow member in contact with the second hollow member. More particularly, it is an object of the present invention to provide a syringe plunger immobilizing device, comprising a first hollow member and a second hollow member, each of the hollow members having a main wall, a first side wall, a second side wall, an outer end wall, a frusto-conical inner end wall and a cylindrical sleeve portion. The cylindrical sleeve portion contacts the inner end wall. The first side wall is connected to the main wall along a first edge of the main wall, and the second side wall is connected to the main wall along a second edge substantially parallel to the first edge such that the first side wall is opposite the second side wall. The outer end wall is connected to the main wall along a third edge of the main wall, with the third edge being substantially perpendicular to the first edge and the second edge. The inner end wall is connected to the main wall along a fourth edge of the main end wall, with the fourth edge being substantially perpendicular to the third edge. The outer end wall is further connected to the first and second side walls such that the outer end wall is opposite the inner end wall. The device further includes a means for hingeably connecting the first hollow member to the second hollow member and a means for holding the first hollow member in contact with the second hollow member when the first hollow member is closed around a syringe plunger and barrel.
It is another object of the present invention to provide a syringe assembly, comprising a disposable or nondisposable syringe and a syringe plunger immobilizing device including a first syringe plunger casing member, a second syringe plunger casing member, and a means for connecting the first syringe plunger casing member to the second syringe plunger casing member.
It is a still further object of the present invention to provide a method for immobilizing a syringe, comprising encasing a syringe plunger of a syringe in a syringe plunger immobilizing device. The syringe plunger immobilizing device contains a first syringe plunger casing member, a second syringe plunger casing member, and a means for connecting the first syringe plunger casing member to the second syringe plunger casing member.
It is a still further object of the present invention to provide a method for manufacturing a syringe plunger immobilizing device, comprising filling a mold with a liquid form of a plastic, forming a molded syringe plunger immobilizing device by hardening the liquid form of a plastic, and removing the molded syringe plunger immobilizing device to form the syringe plunger immobilizing device. The present invention also provides a syringe plunger immobilizing device made by this method.
Other features and advantages of the present invention will be come apparent from the following description of the preferred embodiments, which, when taken in conjunction with the accompanying drawings, illustrate the principles of the invention.